The default CDR settings for Aurora are set to support a +/- 200ppm difference between channel partners.
If the channel partners are synchronous or have a difference < +/-200ppm in the design, a different value for the CDR setting (PMA_RX_CFG) needs to be used to enable only the first order loop.
Below are the settings for PMA_RX_CFG:
clocking: 0x05CE008 - first order loop enabled.
clocking: 0x05CE049 - second order loop enabled.
5/30/2014 - Initial Release